C++ MyMesh::normal方法代码示例

/*Get normal vectors from OpenMesh library
-> bilateral filter denoising of vertices*/
void BilateralDenoise(MyMesh &mesh)
{
	/*ANN kd-tree find nearest point*/
	ANNpointArray	meshArray;				// mesh points array
	ANNpoint		Pt;						// point
	ANNkd_tree*		kdTree;					// search structure

	int PtNum = mesh.n_vertices();
	meshArray = annAllocPts(PtNum, dim);
	Pt = annAllocPt(dim);

	//assign mesh points to ANN array
	for (auto it = mesh.vertices_begin(); it != mesh.vertices_end(); ++it)
	{   
		//Pt get the space of data array
		double getPt[3] = {};

		//Pt get the coordinates of mesh point
		int index = it->idx();
		Pt = meshArray[index];
		for(int d = 0;d < dim; d++)
		{
			getPt[d] = *(mesh.point(it).data()+d);
			Pt[d] = getPt[d];
		}
		//assign Pt coordinates to data array
		meshArray[index] = Pt;
	}

	//build kd-tree
	kdTree = new ANNkd_tree(	// build search structure
		meshArray,				// the data points
		PtNum,					// number of points
		dim);					// dimension of space

	/*Request vertex normal*/
	// request vertex normals, so the mesh reader can use normal information
	// if available
	mesh.request_vertex_normals();

	OpenMesh::IO::Options opt;

	// If the file did not provide vertex normals, then calculate them
	if ( !opt.check( OpenMesh::IO::Options::VertexNormal ) )
	{
		// we need face normals to update the vertex normals
		mesh.request_face_normals();
		// let the mesh update the normals
		mesh.update_normals();

		// dispose the face normals, as we don't need them anymore
		mesh.release_face_normals();
	}

	/*Bilateral filtering*/
	//initial parameters for denoising
	double radius  = 0.0;
	double sigma_c = 0.05; //depend on the distance of the points
	double sigma_s = 0.0;
	int neighbour_num = 12;

	//get certain neighbour and denoise
	for (auto it = mesh.vertices_begin(); it != mesh.vertices_end(); ++it)
	{   
		//Pt get the coordinates from mesh array
		int index = it->idx();
		Pt = meshArray[index];
		std::vector<MyMesh::Point> neighbours;
		vector<double> distVector;

		//Find K(neighbours for normal calculation) nearest neighbours, 
		//return neighbours,distVector,radius
		FindNeighbours(neighbour_num,kdTree,meshArray,Pt,
			neighbours,distVector,radius);

		//get height from current vertex to tangent plane
		//update neighbour number
		neighbour_num = neighbours.size();
		vector<double> height;
		double mean_height = 0.0;
		for(int i=0;i<neighbour_num;i++)
		{
			MyMesh::Point  current_neighbour;
			current_neighbour = neighbours.at(i);

			//get normal vector from normal mesh
			double normal_vector[3]={};
			normal_vector[0]= *mesh.normal(it).data();
			normal_vector[1]= *(mesh.normal(it).data()+1);
			normal_vector[2]= *(mesh.normal(it).data()+2);

			//calculate height
			height.push_back((Pt[0]-current_neighbour.data()[0])*normal_vector[0]+(Pt[1]-current_neighbour.data()[1])*normal_vector[1]+(Pt[2]-current_neighbour.data()[2])*normal_vector[2]);
			mean_height += height.at(i);
		}

		//Calculate standard deviation(sigma_s)
		mean_height /= neighbour_num;
//.........这里部分代码省略.........